This quiz works best with JavaScript enabled. Home > Cbse > Class 11 > Science > Chemistry Part Ii > Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions – Quiz 7 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 7 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The oxidation number for a pure element is? A) -2. B) -1. C) +1. D) 0. E) +2. Show Answer Correct Answer: D) 0. 2. Which of the following is the correct half-reaction for the oxidation process in a redox reaction? A) $O_2 + 4e^-\rightarrow 2O^{2-}$. B) $Zn \rightarrow Zn^{2+} + 2e^-$. C) $2H^+ + 2e^-\rightarrow H_2$. D) $Cu^{2+} + 2e^-\rightarrow Cu$. Show Answer Correct Answer: B) $Zn \rightarrow Zn^{2+} + 2e^-$. 3. In the half equation:Cu $\rightarrow$ Cu$^{2+}$ + 2e$^{-}$Copper undergoes ..... A) Oxidation. B) Reduction. C) Spectatorship. D) Deprotonation. Show Answer Correct Answer: A) Oxidation. 4. What is the oxidation number of chlorine in ClO3-? A) 0. B) +3. C) +5. D) -1. Show Answer Correct Answer: C) +5. 5. Which of the following is not a reduction. A) Zn $\rightarrow$ ZnO. B) C $\rightarrow$ CH$_{4}$. C) Fe$^{3+}$ $\rightarrow$ Fe$^{2+}$. D) Cl$_{2}$ $\rightarrow$ 2Cl$^{-}$. Show Answer Correct Answer: A) Zn $\rightarrow$ ZnO. 6. Which of the following half-reactions represents the reduction process? A) $Cl_2 + 2e^-\rightarrow 2Cl^-$. B) $Fe^{2+} \rightarrow Fe^{3+} + e^-$. C) $Zn \rightarrow Zn^{2+} + 2e^-$. D) $H_2 \rightarrow 2H^+ + 2e^-$. Show Answer Correct Answer: A) $Cl_2 + 2e^-\rightarrow 2Cl^-$. 7. Oxidation is the ..... of electrons. A) Gain. B) Loss. C) Transfer. D) Sharing. Show Answer Correct Answer: B) Loss. 8. Which substance is a reducing agent? A) Acidified hydrogen peroxide solution. B) Iron (III) nitrate solution. C) Potassium iodide solution. D) Acidified potassium manganate (VII) solution. Show Answer Correct Answer: C) Potassium iodide solution. 9. Which of following is incorrect about oxidation? A) Increase in oxidation state. B) Addition of electopositive element. C) Loss of electron. D) Addition of oxygen. Show Answer Correct Answer: B) Addition of electopositive element. 10. An Oxidation number can be A) Zero. B) Negative. C) Positive. D) All of Above. Show Answer Correct Answer: D) All of Above. 11. What is the oxidation number of Ca in CaCl$_{2}$? A) +1. B) -2. C) +2. D) -1. Show Answer Correct Answer: C) +2. 12. What is the reducing agent here:N$_{2}$ + 3H$_{2}$ $\rightarrow$ 2H$_{3}$N A) N$_{2}$. B) H$_{2}$. C) H$_{3}$N. D) None of these is the reducing agent. Show Answer Correct Answer: B) H$_{2}$. 13. What is the oxidation state of nitrogen in dinitrogen oxide, N$_{2}$O? A) +2. B) +1. C) -1. D) -2. Show Answer Correct Answer: B) +1. 14. Name the following ionic compound:Cs$_{2}$S A) Cesium (II) sulfide. B) Cesium sulfide. C) Cesium sulfate. D) Cesium (II) sulfate. Show Answer Correct Answer: B) Cesium sulfide. 15. Defined as the loss of electrons. A) Redox. B) Oxidation. C) OIL RIG. D) Reduction. Show Answer Correct Answer: B) Oxidation. 16. Balance the following half reaction in acidic medium and determine the no. of mole of electrons present in it.NO$_{3}$$^{-}$$\rightarrow$ NO A) 3. B) 1. C) 4. D) 2. Show Answer Correct Answer: A) 3. 17. Is this oxidation or reduction:SO$_{4}$$^{2-}$becomes SO$_{2}$ A) Oxidation. B) Reduction. C) Neither. D) Both. Show Answer Correct Answer: B) Reduction. 18. What is the role of a reductant? A) To undergo reduction by giving up electrons. B) To undergo reduction by gaining electrons. C) To undergo oxidation by giving up electrons. D) To undergo oxidation by gaining electrons. Show Answer Correct Answer: C) To undergo oxidation by giving up electrons. 19. Balance the following reactions using the half-reaction method.MnO$_{4}$$^{-}$(aq) + H$^{+}$(aq) + I$^{-}$ (aq) $\rightarrow$ Mn$^{2+}$(aq) + I$_{2}$(s)How many electrons did you cross out on both side? A) 2 e$^{-}$. B) 1 e$^{-}$. C) 5 e$^{-}$. D) 10 e$^{-}$. Show Answer Correct Answer: D) 10 e$^{-}$. 20. Which reagent would be best for the selective reduction of an aldehyde? A) $NaBH_4$. B) $H_2$. C) $LiAlH_4$. D) $OsO_{4_{ }}$. Show Answer Correct Answer: A) $NaBH_4$. 21. Which is true about voltaic cells? A) The anode is positive. B) Reduction is at the cathode. C) The reactions are nonspontaneous. D) Convert electrical energy into chemical energy. Show Answer Correct Answer: B) Reduction is at the cathode. 22. In the reaction Zn + 2HCl $\rightarrow$ ZnCl$_{2}$ + H$_{2}$which element, if any, is reducing agent? A) None. B) Hydrogen. C) Chlorine. D) Zinc. Show Answer Correct Answer: D) Zinc. 23. A solution of sulfuric acid is added to a solution of barium hydroxide; What is the net ionic equation? A) H$^{+}$ + SO$_{4}$$^{2-}$+ Ba$^{2+}$ + OH$^{-}$$\rightarrow$BaSO$_{4}$ + H$_{2}$O. B) H$_{2}$SO$_{4}$$^{ }$+ Ba$^{2+}$ + OH$^{-}$$\rightarrow$BaSO$_{4}$ + H$_{2}$O. C) H$^{+}$ + OH$^{-}$$\rightarrow$ H$_{2}$O. D) H$_{2}$SO$_{4}$$^{ }$+ Ba$^{2+}$ + OH$^{-}$$\rightarrow$Ba$^{2+}$+ SO$_{4}$ $^{2-}$+ H$_{2}$O. Show Answer Correct Answer: A) H$^{+}$ + SO$_{4}$$^{2-}$+ Ba$^{2+}$ + OH$^{-}$$\rightarrow$BaSO$_{4}$ + H$_{2}$O. 24. What happens to the oxidation state of an element that is reduced in a redox reaction? A) It becomes zero. B) It increases. C) It decreases. D) It remains the same. Show Answer Correct Answer: C) It decreases. 25. Explain why the electrolyte has to be a liquid. A) So the ions can move. B) So the fish are ok. C) So that it doesn't get too hot. D) So the electrons can move. Show Answer Correct Answer: A) So the ions can move. 26. What kind of equation is this:2KI + MgCl$_{2}$ + 200KJ $\rightarrow$ 2KCl + MgI$_{2}$ A) Endothermic. B) Exothermic. C) All the above. D) None of the above. Show Answer Correct Answer: A) Endothermic. 27. What is the function of the salt bridge in an electrochemical cell? A) To increase the cell's electrical resistance. B) To provide a path for electrons to move between the electrodes. C) To prevent the electrodes from physically touching each other. D) To maintain electrical neutrality by allowing the flow of ions. Show Answer Correct Answer: D) To maintain electrical neutrality by allowing the flow of ions. 28. Determine the oxidation number of chromate in CrO$_{4}$$^{2-}$. A) +2. B) +6. C) +3. D) 0. Show Answer Correct Answer: B) +6. 29. Which is true of the colorful electrolysis of water demo? A) Oxygen gas was produced twice as fast. B) It turned purple at the cathode. C) Hydrogen gas was produced at the anode. D) The pH was high where hydrogen gas was produced. Show Answer Correct Answer: B) It turned purple at the cathode. 30. Explain how redox reactions are involved in cellular respiration. A) Redox reactions only occur in photosynthesis. B) Redox reactions in cellular respiration involve the oxidation of glucose and the reduction of oxygen, facilitating energy production. C) Cellular respiration does not involve any electron transfer. D) Oxygen is oxidized while glucose is reduced during respiration. Show Answer Correct Answer: B) Redox reactions in cellular respiration involve the oxidation of glucose and the reduction of oxygen, facilitating energy production. 31. What coefficients are needed to correctly balance the equation? ..... Bi + ..... O$_{2}$$_{ }$ $\rightarrow$ ..... Bi$_{2}$O$_{3}$ A) 3, 2, 3. B) 2, 3, 2. C) 4, 3, 2. D) None of these. Show Answer Correct Answer: C) 4, 3, 2. 32. In a reaction, Iron (II) Sulphate changed colour from green to brown. The reaction that occur is A) Reduction of Fe3+ to Fe2+. B) Oxidation of Fe3+ to Fe2+. C) Oxidation of Fe2+ to Fe3+. D) Reduction of Fe2+ to Fe3+. Show Answer Correct Answer: C) Oxidation of Fe2+ to Fe3+. 33. What is the oxidation number of oxygen in oxygen gas, $O_2$ A) 0. B) -1. C) -2. D) +1. Show Answer Correct Answer: A) 0. 34. Balance the following redox equations for reactions that occur in neutral solution:Zn + Ag+ $\rightarrow$ Zn$^{2+}$ + Ag A) Zn + Ag$^{+}$ $\rightarrow$ Zn$^{2+}$ + Ag. B) Zn+ Ag$^{+}$ $\rightarrow$ 2 Zn$^{2+ }$+ 2Ag. C) Zn + 2Ag$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2Ag. D) Zn + 2Ag$^{+}$ $\rightarrow$ Zn$^{2+}$ + Ag. Show Answer Correct Answer: C) Zn + 2Ag$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2Ag. 35. The strongest reductant from the following list:Fe$^{3+}$; Sn$^{2+}$; H$_{2}$O; K$^{+}$; Br$^{-}$; Au; Pb$^{2+}$ is A) Au. B) Fe$^{3+}$. C) Sn$^{2+}$. D) K$^{+}$. Show Answer Correct Answer: C) Sn$^{2+}$. 36. Study this half-reaction:Cu $\rightarrow$ Cu$^{2+}$ + 2e$^{-}$Which statement is INCORRECT? A) Two electrons are released. B) Copper becomes more positively-charged. C) Copper is reduced. D) None of the above. Show Answer Correct Answer: C) Copper is reduced. 37. In the standardisation of Na$_{2}$S$_{2}$O$_{3}$ using K$_{2}$Cr$_{2}$O$_{7}$ by iodometry, the equivalent weight of K$_{2}$Cr$_{2}$O$_{7}$ is: A) Same molecular weight. B) Molecular weight / 6. C) Molecular weight / 2. D) Molecular weight / 3. Show Answer Correct Answer: B) Molecular weight / 6. 38. What is the oxidation state of Cu in Cu$^{2+}$? A) +2. B) -1. C) -2. D) 0. Show Answer Correct Answer: A) +2. 39. Determine the oxidation number of Chromium in CrO$_{4}$$^{2-}$. A) +3. B) +6. C) +2. D) 0. Show Answer Correct Answer: B) +6. 40. What is an oxidation state? A) The physical state the element is in before a reaction. B) The number of atoms of that element in a compound. C) The number of electrons transferred in the reaction. D) The charge an element would have if it were an ion. Show Answer Correct Answer: D) The charge an element would have if it were an ion. 41. How does the electrochemical series help in designing galvanic cells? A) By providing the color of the electrodes for aesthetic design. B) By indicating the solubility of electrolytes in water. C) By predicting the spontaneity of redox reactions and determining the direction of electron flow. D) By determining the size of the cell components. Show Answer Correct Answer: C) By predicting the spontaneity of redox reactions and determining the direction of electron flow. 42. What is the oxidation number of chlorine in HClO? A) -1. B) 0. C) +1. D) +5. Show Answer Correct Answer: C) +1. 43. NADH is a ..... form of NAD+. A) Catabolized. B) Reduced. C) Hydrolized. D) Oxidized. Show Answer Correct Answer: B) Reduced. 44. Which type of reaction is this?P$_{4}$ + 3NaOH + 3H$_{2}$O $\rightarrow$ 3NaH$_{2}$PO$_{2}$ + PH$_{3}$ A) Oxidation. B) Reduction. C) Disproportionation. D) None. Show Answer Correct Answer: C) Disproportionation. 45. In the context of balancing redox equations, what does it mean to "balance the charge" ? A) Ensuring that the same number of electrons is produced and consumed. B) Making sure the total number of atoms is the same on both sides of the equation. C) Adjusting the pH of the solution. D) Adding water molecules to balance the hydrogen atoms. Show Answer Correct Answer: A) Ensuring that the same number of electrons is produced and consumed. 46. Acidified potassium manganate (VII) is a strong oxidizing agent. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 47. Determine the oxidation number of each element in XeO$_{4}$$^{-2}$ A) Xe:+8, O:-2. B) Xe:+6, O:-6. C) Xe:-8, O:+8. D) Xe:+6, O:-2. Show Answer Correct Answer: D) Xe:+6, O:-2. 48. A/an ..... agent is a substance that has the potential to cause another substance to be oxidized. A) Biological. B) Reducing. C) Oxidizing. D) Chemical. Show Answer Correct Answer: C) Oxidizing. 49. ..... electrode is an inert electrode. A) Carbon. B) Iron. C) Zinc. D) Copper. Show Answer Correct Answer: A) Carbon. 50. What does it mean if a substance is reduced? A) It means it has lost electrons and its oxidation state has increased. B) It means it has gained electrons and its oxidation state has decreased. C) It means it has remained unchanged in terms of electrons and oxidation state. D) It means it has been converted into a gas. Show Answer Correct Answer: B) It means it has gained electrons and its oxidation state has decreased. 51. A fuel cell ..... A) Does not form any products. B) Produces its own fuel. C) Has a negative cell potential. D) Uses a spontaneous reaction to generate electricity. Show Answer Correct Answer: D) Uses a spontaneous reaction to generate electricity. 52. In a redox reaction, the species that loses electrons ..... A) Is called the cathode. B) Is oxidized. C) Decreases in oxidation number. D) Gains mass at the electrode. Show Answer Correct Answer: B) Is oxidized. 53. What is the oxidation number of iodine in KIO$_{3}$? A) 1. B) -1. C) 5. D) 0. Show Answer Correct Answer: C) 5. 54. Which of the following will not show disproportionation reaction: A) ClO$_{2}$$^{-}$. B) ClO$^{-}$. C) ClO$_{3}$$^{-}$. D) ClO$_{4}$$^{-}$. Show Answer Correct Answer: D) ClO$_{4}$$^{-}$. 55. Does every element have only one single oxidation number? A) Yes. B) No. C) Maybe so. D) None of the above. Show Answer Correct Answer: B) No. 56. Why is oxygen considered the quintessential oxidizer? A) It stabilizes molecules by adding electrons. B) It donates electrons to other molecules. C) It always gains protons in reactions. D) It pulls electrons off of one molecule to make itself more stable. Show Answer Correct Answer: D) It pulls electrons off of one molecule to make itself more stable. 57. What type of reaction is represented by 2Na + Cl2 $\rightarrow$ 2NaCl? A) Redox. B) Decomposition. C) Combination. D) Displacement. Show Answer Correct Answer: C) Combination. 58. A redox reaction is A) A neutralization reaction. B) All reactions. C) A reaction in which electrons are transferred from one element to another. D) Non of these are correct. Show Answer Correct Answer: C) A reaction in which electrons are transferred from one element to another. 59. What is the name of the negative electrode? A) Cathode. B) Anode. C) All the above. D) None of the above. Show Answer Correct Answer: A) Cathode. 60. What is the oxidizing agent of this reaction?3Mg + N$_{2 }$$\rightarrow$ Mg$_{3}$N$_{2}$ A) N$_{2}$. B) Mg$_{3}$N$_{2}$. C) MgN. D) Mg. Show Answer Correct Answer: A) N$_{2}$. ← PreviousNext →Related QuizzesScience QuizzesClass 11 QuizzesClass 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 1Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 2Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 3Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 4Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 5Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 6Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 8Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books